Many types of Micro Electro-Mechanical Systems (MEMS) provide electrical sensing, controls, and calculation. MEMS technology is being applied to continually smaller systems, and recently has been applied to nano-scale systems. Designing for continually smaller devices, particularly down to and into the nano-scale dimensions, provides considerable design challenges.
Considerable complexity results when MEMS devices and circuits are applied to hostile environments. One of the most challenging environments that MEMS, or any electronic circuit, can be designed for, or applied to is fluids (and more particularly blood, other bodily fluids, or difficult to handle fluids). MEMS can be configured to sense or monitor a variety of parameters within the human body as well as in many other applications. The electronic device has to be protected from such hostile environments to provide an accurate measurement of the fluid.
One prior art embodiment of a MEMS device 29, as illustrated in FIG. 1, can be integrated within certain chemical analysis systems. The MEMS device 29 includes a plurality of substrates 34 and 36. Grooves and/or channels 28 are etched into one or both of the respective etched faces 30, 32 of the two respective substrates 34, 36. The etched faces of each one of the two substrates are bonded together at a bonded region 38 as illustrated in FIG. 2 such that they are positioned to face each other. Since the etched faces are mounted to face each other, a pair of etched grooves (i.e., one groove in each of the etched faces) can together form a conduit surrounded on each side by one of the substrates.
The substrates 34, 36 can be manufactured from a glass (such as Pyrex®—a trademark of Corning) or a semiconductor such as silicon. The substrates are bonded together so the etched channels and/or grooves 28 (as shown in FIG. 1) in one or both of the etched faces 30, 32 of the substrates form a conduit that provides fluidic communications. The substrates can be bonded using anodic bonding technique or with glass frit intermediate layers. The conduits that provide fluidic communications include fluidic I/O ports as well as the fluidic channels.
Such prior art techniques can use known fabrication to create the etched channels and/or grooves 28 as shown in FIG. 1 having a desired dimension down to, and including, tens of nanometers. However, aligning the etched channels and/or grooves 28 on pairs of bonded substrates takes a considerable amount of time and effort. As such, it is difficult to use such matched substrate configurations in large scale production. In addition, such bonded substrate pairs are costly to produce.